Data commit

Task/Arithmetic-numbers/Lua/arithmetic-numbers.lua

@@ -0,0 +1,58 @@
+local function factors (n)
+	local f, i = {1, n}, 2
+	while true do
+		local j = n//i -- floor division by Lua 5.3
+		if j < i then
+			break
+		elseif j == i and i * j == n then
+			table.insert (f, i)
+			break
+		elseif i * j == n then
+			table.insert (f, i)
+			table.insert (f, j)
+		end
+		i = i + 1
+	end
+	return f
+end
+
+local function sum (f)
+	local s = 0
+	for i, value in ipairs (f) do
+		s = s + value
+	end
+	return s
+end
+
+local arithmetic_count = 1
+local composite_count = 0
+local hundr = {1}
+
+for n = 2, 1228663 do
+	local f = factors (n)
+	local s = sum (f)
+	local l = #f
+	if (s/l)%1 == 0 then
+		arithmetic_count = arithmetic_count + 1
+		if l > 2 then
+			composite_count = composite_count + 1
+		end
+		if arithmetic_count <= 100 then
+			table.insert (hundr, n)
+		end
+		if arithmetic_count == 100 then
+			for i = 0, 9 do
+				print (table.concat(hundr, ',	', 10*i+1, 10*i+10))
+			end
+		elseif arithmetic_count == 1000
+			or arithmetic_count == 10000
+			or arithmetic_count == 100000 then
+			print (arithmetic_count..'th arithmetic number is '..(n))
+			print ('Number of composite arithmetic numbers <= '..(n)..': '..composite_count)
+		elseif arithmetic_count == 1000000 then
+			print (arithmetic_count..'th arithmetic number is '..(n))
+			print ('Number of composite arithmetic numbers <= '..(n)..': '..composite_count)
+			return
+		end
+	end
+end